/*
 * Copyright (C) 2005 Luca Veltri - University of Parma - Italy
 *
 * This file is part of MjSip (http://www.mjsip.org)
 *
 * MjSip is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * MjSip is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with MjSip; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author(s):
 * Luca Veltri (luca.veltri@unipr.it)
 */

package org.zoolu.tools;



/** MD5 hash algorithm.
 * <p> Implements the RSA Data Security, Inc. MD5 Message-Digest Algorithm.
 * This is almost straight implementation of the reference implementation
 * given in RFC1321 by RSA.
 * <p/>
 * Note: It seems to be faster then the JDK1.4 MD5 implementation (java.security.MessageDigest.getInstance("MD5")).
 */
public class MD5 extends MessageDigest
{

    // ********************** Mangle functions **********************

    /** Rotates w, shifting n bits left. */
    //private static int rotateLeft(int w, int n) {  return (w << n) | (w >>> (32-n));  }

    /** Rotates w, shifting n bits right. */
    //private static int rotateRight(int w, int n) {  return (w >>> n) | (w << (32-n));  }

    /** Rotates an array of words, shifting 1 word left. */
   /*private static int[] rotateLeft(int[] w)
   {  int len=w.length;
      int w1=w[len-1];
      for (int i=len-1; i>0; i--) w[i]=w[i-1];
      w[0]=w1;
      return w;
   }*/

    /** Rotates an array of words, shifting 1 word right. */
   /*private static int[] rotateRight(int[] w)
   {  int len=w.length;
      int w0=w[0];
      for (int i=1; i<len; i++) w[i-1]=w[i];
      w[len-1]=w0;
      return w;
   }*/

    /** Gets the unsigned representatin of a byte (into a short) */
    //private static short uByte(byte b) {  return (short)((int)b&0xFF);  }

    /** 0x00000000FFFFFFFF */
    //private static final long OxFFFFFFFF=((long)1<<32)-1;

    /** Gets the unsigned representatin of a 32-bit word (into a long) */
   /*private static long uWord(int n) {  return (long)n&OxFFFFFFFF;  } 

   /** Copies all bytes of array <i>src</i> into array <i>dst</i> with offset <i>offset</i> */
    //private static void copyBytes(byte[] src, byte[] dst, int offset) { for (int k=0; k<src.length; k++) dst[offset+k]=src[k]; }

    /** Copies the first <i>len</i> bytes of array <i>src</i> into array <i>dst</i> with offset <i>offset</i> */
    //private static void copyBytes(byte[] src, byte[] dst, int offset, int len) { for (int k=0; k<len; k++) dst[offset+k]=src[k]; }

    /** Transforms a 4-bytes array into a 32-bit word (with the more significative byte at left) */
    //private static long bytesToWord(byte[] b, int offset) {  return ((((((long)uByte(b[offset+3])<<8)+uByte(b[offset+2]))<<8)+uByte(b[offset+1]))<<8)+uByte(b[offset+0]);  }

    /** Transforms a 4-bytes array into a 32-bit word (with the more significative byte at left) */
    //private static long bytesToWord(byte[] b) {  return ((((((long)uByte(b[3])<<8)+uByte(b[2]))<<8)+uByte(b[1]))<<8)+uByte(b[0]);  }

    /** Transforms a 32-bit word (with the more significative byte at left) into a 4-bytes array */
   /*private static byte[] wordToBytes(long n)
   {  byte[] b=new byte[4];
      b[3]=(byte)(n>>24);
      b[2]=(byte)((n>>16)&0xFF);
      b[1]=(byte)((n>>8)&0xFF);
      b[0]=(byte)(n&0xFF);
      return b;
   }*/


    // ************************* Attributes *************************

    /** The digest */
    byte[] message_digest;

    /** byte counter mod 2^64 */
    long count;

    /** 128bit state (A,B,C, and D words) */
    int state[];

    /** 64B (512 bits) chunk of the input message */
    byte block[];

    /** Number of bytes remained into the chunk */
    int block_offset;

    /** Padding */
    static byte zeropadding[]= { (byte)0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };


    /* Constants for MD5 transformation */
   /*
   static final int S11=7;
   static final int S12=12;
   static final int S13=17;
   static final int S14=22;
   static final int S21=5;
   static final int S22=9;
   static final int S23=14;
   static final int S24=20;
   static final int S31=4;
   static final int S32=11;
   static final int S33=16;
   static final int S34=23;
   static final int S41=6;
   static final int S42=10;
   static final int S43=15;
   static final int S44=21;
   */


    // *********************** Public methods ***********************

    /** Constructor */
    public MD5()
    {  init();
    }


    /** Constructor */
    public MD5(byte[] buffer)
    {  init();
        update(buffer);
    }


    /** Constructor */
    public MD5(byte[] buffer, int offset, int len)
    {  init();
        update(buffer,offset,len);
    }


    /** Constructor */
    public MD5(String str)
    {  init();
        update(str);
    }


    /** Inits the MD5 */
    private void init()
    {  count=0;
        // init the first block
        block=new byte[64];
        block_offset=0;
        // load magic initialization constants
        state=new int[4];
        state[0]=0x67452301;
        state[1]=0xefcdab89;
        state[2]=0x98badcfe;
        state[3]=0x10325476;

        message_digest=null;
    }


    /** MessageDigest block update operation.
     * Continues a message-digest operation,
     * processing another message block, and updating the context. */
   /*public MD5 update(String str)
   {  byte[] buf=str.getBytes();
      return update(buf,0,buf.length);
   }*/


    /** MessageDigest block update operation.
     * Continues a message-digest operation,
     * processing another message block, and updating the context. */
   /*public MD5 update(byte[] buffer)
   {  return update(buffer,0,buffer.length);
   }*/


    /** MessageDigest block update operation.
     * Continues a message-digest operation,
     * processing another message block, and updating the context. */
    public MessageDigest update(byte[] buffer, int offset, int len)
    {
        if (message_digest!=null) return this;
        //else

        count+=len;

        // num of remaining bytes to be processed
        int size=block.length-block_offset;

        while(len>=size)
        {  // fill a block
            for (int i=0; i<size; i++) block[block_offset+i]=buffer[offset+i];

            // process the block
            transform(state,block);

            // update offset, len, etc.
            offset+=size;
            len-=size;
            block_offset=0;
            size=block.length-block_offset;
        }
        // copy the remaining bytes
        for (int i=0; i<len; i++) block[block_offset+i]=buffer[offset+i];
        block_offset+=len;

        return this;
    }


    /** Gets the MessageDigest. The same as doFinal(). */
   /*public byte[] getDigest()
   {  return doFinal();
   }*/


    /** MessageDigest finalization. Ends a message-digest operation, writing the
     * the message digest and zeroizing the context. */
    public byte[] doFinal()
    {
        if (message_digest!=null) return message_digest;
        //else

        // num of padding zeros (node: block_offset is at most 64)
        int npad=64-((block_offset+8)%64);

        // set total bit length into the last 8 bytes
        long len=count*8;
        byte[] len_field=new byte[8];
        for (int i=0; i<8; i++) {  len_field[i]=(byte)(len%256); len>>=8;  }

        // process the last chunk, i.e. zero-pading(1-64B) + length-field(8B) (1 or 2 blocks)
        update(zeropadding,0,npad);
        update(len_field,0,8);

        message_digest=new byte[16];
        // convert 4 words to 16 bytes
        //for (int i=0; i<4; i++) {  copyBytes(wordToBytes(state[i]),message_digest,i*4);  }
        int k=0;
        for (int i=0; i<4; i++)
        {  message_digest[k++]=(byte)((state[i]) & 0xff);
            message_digest[k++]=(byte)((state[i]>>>8) & 0xff);
            message_digest[k++]=(byte)((state[i]>>>16) & 0xff);
            message_digest[k++]=(byte)((state[i]>>>24) & 0xff);
        }
        return message_digest;
    }


    /** MD5 basic transformation. Transforms state based on block. */
    private static void transform(int[] state, byte[] block)
    {
        int a=state[0];
        int b=state[1];
        int c=state[2];
        int d=state[3];

        int[] x=new int[16];
        x[0]=((int) (block[0] & 0xff)) |
                (((int) (block[1] & 0xff)) << 8) |
                (((int) (block[2] & 0xff)) << 16) |
                (((int) (block[3])) << 24);
        x[1]=((int) (block[4] & 0xff)) |
                (((int) (block[5] & 0xff)) << 8) |
                (((int) (block[6] & 0xff)) << 16) |
                (((int) (block[7])) << 24);
        x[2]=((int) (block[8] & 0xff)) |
                (((int) (block[9] & 0xff)) << 8) |
                (((int) (block[10] & 0xff)) << 16) |
                (((int) (block[11])) << 24);
        x[3]=((int) (block[12] & 0xff)) |
                (((int) (block[13] & 0xff)) << 8) |
                (((int) (block[14] & 0xff)) << 16) |
                (((int) (block[15])) << 24);
        x[4]=((int) (block[16] & 0xff)) |
                (((int) (block[17] & 0xff)) << 8) |
                (((int) (block[18] & 0xff)) << 16) |
                (((int) (block[19])) << 24);
        x[5]=((int) (block[20] & 0xff)) |
                (((int) (block[21] & 0xff)) << 8) |
                (((int) (block[22] & 0xff)) << 16) |
                (((int) (block[23])) << 24);
        x[6]=((int) (block[24] & 0xff)) |
                (((int) (block[25] & 0xff)) << 8) |
                (((int) (block[26] & 0xff)) << 16) |
                (((int) (block[27])) << 24);
        x[7]=((int) (block[28] & 0xff)) |
                (((int) (block[29] & 0xff)) << 8) |
                (((int) (block[30] & 0xff)) << 16) |
                (((int) (block[31])) << 24);
        x[8]=((int) (block[32] & 0xff)) |
                (((int) (block[33] & 0xff)) << 8) |
                (((int) (block[34] & 0xff)) << 16) |
                (((int) (block[35])) << 24);
        x[9]=((int) (block[36] & 0xff)) |
                (((int) (block[37] & 0xff)) << 8) |
                (((int) (block[38] & 0xff)) << 16) |
                (((int) (block[39])) << 24);
        x[10]=((int)(block[40] & 0xff)) |
                (((int) (block[41] & 0xff)) << 8) |
                (((int) (block[42] & 0xff)) << 16) |
                (((int) (block[43])) << 24);
        x[11]=((int)(block[44] & 0xff)) |
                (((int) (block[45] & 0xff)) << 8) |
                (((int) (block[46] & 0xff)) << 16) |
                (((int) (block[47])) << 24);
        x[12]=((int)(block[48] & 0xff)) |
                (((int) (block[49] & 0xff)) << 8) |
                (((int) (block[50] & 0xff)) << 16) |
                (((int) (block[51])) << 24);
        x[13]=((int)(block[52] & 0xff)) |
                (((int) (block[53] & 0xff)) << 8) |
                (((int) (block[54] & 0xff)) << 16) |
                (((int) (block[55])) << 24);
        x[14]=((int)(block[56] & 0xff)) |
                (((int) (block[57] & 0xff)) << 8) |
                (((int) (block[58] & 0xff)) << 16) |
                (((int) (block[59])) << 24);
        x[15]=((int)(block[60] & 0xff)) |
                (((int) (block[61] & 0xff)) << 8) |
                (((int) (block[62] & 0xff)) << 16) |
                (((int) (block[63])) << 24);

        /* Round 1 */
        a+= ((b & c) | (~b & d)) + x[ 0] + 0xd76aa478;
        a = ((a << 7) | (a >>> 25)) + b;
        d+= ((a & b) | (~a & c)) + x[ 1] + 0xe8c7b756;
        d = ((d << 12) | (d >>> 20)) + a;
        c+= ((d & a) | (~d & b)) + x[ 2] + 0x242070db;
        c = ((c << 17) | (c >>> 15)) + d;
        b+= ((c & d) | (~c & a)) + x[ 3] + 0xc1bdceee;
        b = ((b << 22) | (b >>> 10)) + c;

        a+= ((b & c) | (~b & d)) + x[ 4] + 0xf57c0faf;
        a = ((a << 7) | (a >>> 25)) + b;
        d+= ((a & b) | (~a & c)) + x[ 5] + 0x4787c62a;
        d = ((d << 12) | (d >>> 20)) + a;
        c+= ((d & a) | (~d & b)) + x[ 6] + 0xa8304613;
        c = ((c << 17) | (c >>> 15)) + d;
        b+= ((c & d) | (~c & a)) + x[ 7] + 0xfd469501;
        b = ((b << 22) | (b >>> 10)) + c;

        a+= ((b & c) | (~b & d)) + x[ 8] + 0x698098d8;
        a = ((a << 7) | (a >>> 25)) + b;
        d+= ((a & b) | (~a & c)) + x[ 9] + 0x8b44f7af;
        d = ((d << 12) | (d >>> 20)) + a;
        c+= ((d & a) | (~d & b)) + x[10] + 0xffff5bb1;
        c = ((c << 17) | (c >>> 15)) + d;
        b+= ((c & d) | (~c & a)) + x[11] + 0x895cd7be;
        b = ((b << 22) | (b >>> 10)) + c;

        a+= ((b & c) | (~b & d)) + x[12] + 0x6b901122;
        a = ((a << 7) | (a >>> 25)) + b;
        d+= ((a & b) | (~a & c)) + x[13] + 0xfd987193;
        d = ((d << 12) | (d >>> 20)) + a;
        c+= ((d & a) | (~d & b)) + x[14] + 0xa679438e;
        c = ((c << 17) | (c >>> 15)) + d;
        b+= ((c & d) | (~c & a)) + x[15] + 0x49b40821;
        b = ((b << 22) | (b >>> 10)) + c;


        /* Round 2 */
        a+= ((b & d) | (c & ~d)) + x[ 1] + 0xf61e2562;
        a = ((a << 5) | (a >>> 27)) + b;
        d+= ((a & c) | (b & ~c)) + x[ 6] + 0xc040b340;
        d = ((d << 9) | (d >>> 23)) + a;
        c+= ((d & b) | (a & ~b)) + x[11] + 0x265e5a51;
        c = ((c << 14) | (c >>> 18)) + d;
        b+= ((c & a) | (d & ~a)) + x[ 0] + 0xe9b6c7aa;
        b = ((b << 20) | (b >>> 12)) + c;

        a+= ((b & d) | (c & ~d)) + x[ 5] + 0xd62f105d;
        a = ((a << 5) | (a >>> 27)) + b;
        d+= ((a & c) | (b & ~c)) + x[10] + 0x02441453;
        d = ((d << 9) | (d >>> 23)) + a;
        c+= ((d & b) | (a & ~b)) + x[15] + 0xd8a1e681;
        c = ((c << 14) | (c >>> 18)) + d;
        b+= ((c & a) | (d & ~a)) + x[ 4] + 0xe7d3fbc8;
        b = ((b << 20) | (b >>> 12)) + c;

        a+= ((b & d) | (c & ~d)) + x[ 9] + 0x21e1cde6;
        a = ((a << 5) | (a >>> 27)) + b;
        d+= ((a & c) | (b & ~c)) + x[14] + 0xc33707d6;
        d = ((d << 9) | (d >>> 23)) + a;
        c+= ((d & b) | (a & ~b)) + x[ 3] + 0xf4d50d87;
        c = ((c << 14) | (c >>> 18)) + d;
        b+= ((c & a) | (d & ~a)) + x[ 8] + 0x455a14ed;
        b = ((b << 20) | (b >>> 12)) + c;

        a+= ((b & d) | (c & ~d)) + x[13] + 0xa9e3e905;
        a = ((a << 5) | (a >>> 27)) + b;
        d+= ((a & c) | (b & ~c)) + x[ 2] + 0xfcefa3f8;
        d = ((d << 9) | (d >>> 23)) + a;
        c+= ((d & b) | (a & ~b)) + x[ 7] + 0x676f02d9;
        c = ((c << 14) | (c >>> 18)) + d;
        b+= ((c & a) | (d & ~a)) + x[12] + 0x8d2a4c8a;
        b = ((b << 20) | (b >>> 12)) + c;


        /* Round 3 */
        a+= (b ^ c ^ d) + x[ 5] + 0xfffa3942;
        a = ((a << 4) | (a >>> 28)) + b;
        d+= (a ^ b ^ c) + x[ 8] + 0x8771f681;
        d = ((d << 11) | (d >>> 21)) + a;
        c+= (d ^ a ^ b) + x[11] + 0x6d9d6122;
        c = ((c << 16) | (c >>> 16)) + d;
        b+= (c ^ d ^ a) + x[14] + 0xfde5380c;
        b = ((b << 23) | (b >>> 9)) + c;

        a+= (b ^ c ^ d) + x[ 1] + 0xa4beea44;
        a = ((a << 4) | (a >>> 28)) + b;
        d+= (a ^ b ^ c) + x[ 4] + 0x4bdecfa9;
        d = ((d << 11) | (d >>> 21)) + a;
        c+= (d ^ a ^ b) + x[ 7] + 0xf6bb4b60;
        c = ((c << 16) | (c >>> 16)) + d;
        b+= (c ^ d ^ a) + x[10] + 0xbebfbc70;
        b = ((b << 23) | (b >>> 9)) + c;

        a+= (b ^ c ^ d) + x[13] + 0x289b7ec6;
        a = ((a << 4) | (a >>> 28)) + b;
        d+= (a ^ b ^ c) + x[ 0] + 0xeaa127fa;
        d = ((d << 11) | (d >>> 21)) + a;
        c+= (d ^ a ^ b) + x[ 3] + 0xd4ef3085;
        c = ((c << 16) | (c >>> 16)) + d;
        b+= (c ^ d ^ a) + x[ 6] + 0x04881d05;
        b = ((b << 23) | (b >>> 9)) + c;

        a+= (b ^ c ^ d) + x[ 9] + 0xd9d4d039;
        a = ((a << 4) | (a >>> 28)) + b;
        d+= (a ^ b ^ c) + x[12] + 0xe6db99e5;
        d = ((d << 11) | (d >>> 21)) + a;
        c+= (d ^ a ^ b) + x[15] + 0x1fa27cf8;
        c = ((c << 16) | (c >>> 16)) + d;
        b+= (c ^ d ^ a) + x[ 2] + 0xc4ac5665;
        b = ((b << 23) | (b >>> 9)) + c;


        /* Round 4 */
        a+= (c ^ (b | ~d)) + x[ 0] + 0xf4292244;
        a = ((a << 6) | (a >>> 26)) + b;
        d+= (b ^ (a | ~c)) + x[ 7] + 0x432aff97;
        d = ((d << 10) | (d >>> 22)) + a;
        c+= (a ^ (d | ~b)) + x[14] + 0xab9423a7;
        c = ((c << 15) | (c >>> 17)) + d;
        b+= (d ^ (c | ~a)) + x[ 5] + 0xfc93a039;
        b = ((b << 21) | (b >>> 11)) + c;

        a+= (c ^ (b | ~d)) + x[12] + 0x655b59c3;
        a = ((a << 6) | (a >>> 26)) + b;
        d+= (b ^ (a | ~c)) + x[ 3] + 0x8f0ccc92;
        d = ((d << 10) | (d >>> 22)) + a;
        c+= (a ^ (d | ~b)) + x[10] + 0xffeff47d;
        c = ((c << 15) | (c >>> 17)) + d;
        b+= (d ^ (c | ~a)) + x[ 1] + 0x85845dd1;
        b = ((b << 21) | (b >>> 11)) + c;

        a+= (c ^ (b | ~d)) + x[ 8] + 0x6fa87e4f;
        a = ((a << 6) | (a >>> 26)) + b;
        d+= (b ^ (a | ~c)) + x[15] + 0xfe2ce6e0;
        d = ((d << 10) | (d >>> 22)) + a;
        c+= (a ^ (d | ~b)) + x[ 6] + 0xa3014314;
        c = ((c << 15) | (c >>> 17)) + d;
        b+= (d ^ (c | ~a)) + x[13] + 0x4e0811a1;
        b = ((b << 21) | (b >>> 11)) + c;

        a+= (c ^ (b | ~d)) + x[ 4] + 0xf7537e82;
        a = ((a << 6) | (a >>> 26)) + b;
        d+= (b ^ (a | ~c)) + x[11] + 0xbd3af235;
        d = ((d << 10) | (d >>> 22)) + a;
        c+= (a ^ (d | ~b)) + x[ 2] + 0x2ad7d2bb;
        c = ((c << 15) | (c >>> 17)) + d;
        b+= (d ^ (c | ~a)) + x[ 9] + 0xeb86d391;
        b = ((b << 21) | (b >>> 11)) + c;

        state[0]+= a;
        state[1]+= b;
        state[2]+= c;
        state[3]+= d;
    }


    /** F MD5 function. */
    //private static int F(int x, int y, int z) {  return (x & y) | ((~x) & z);  }
    /** G MD5 function. */
    //private static int G(int x, int y, int z) {  return (x & z) | (y & (~z));  }
    /** H MD5 function. */
    //private static int H(int x, int y, int z) {  return (x ^ y ^ z);  }
    /** I MD5 function. */
    //private static int I(int x, int y, int z) {  return y ^ (x | (~z));  }


    /** FF transformation for round 1.
     Rotation is separate from addition to prevent recomputation. */
   /*private static int[] FF(int[] w, int x, int s, int t)
   {  w[0] += F(w[1],w[2],w[3]) + x + t;
      w[0] = rotateLeft(w[0],s) + w[1];
      return rotateLeft(w);
   }*/
    /** GG transformation for round 2.
     Rotation is separate from addition to prevent recomputation. */
   /*private static int[] GG(int[] w, int x, int s, int t)
   {  w[0] += G(w[1],w[2],w[3]) + x + t;
      w[0] = rotateLeft(w[0],s) + w[1];
      return rotateLeft(w);
   }*
   /** HH transformation for round 3.
       Rotation is separate from addition to prevent recomputation. */
   /*private static int[] HH(int[] w, int x, int s, int t)
   {  w[0] += H(w[1],w[2],w[3]) + x + t;
      w[0] = rotateLeft(w[0],s) + w[1];
      return rotateLeft(w);
   }*
   /** II transformation for round 4.
       Rotation is separate from addition to prevent recomputation. */
   /*private static int[] II(int[] w, int x, int s, int t)
   {  w[0] += I(w[1],w[2],w[3]) + x + t;
      w[0] = rotateLeft(w[0],s) + w[1];
      return rotateLeft(w);
   }*/


    /** MD5 basic transformation. Transforms state based on block. */
   /*private static void transform(int[] state, byte[] block)
   {
      int[] x=new int[16];
      for (int i=0; i<16; i++) x[i]=(int)bytesToWord(block,(i*4));
      
      // make a copy of the state
      int[] state_cp=new int[4];
      for (int i=0; i<4; i++) state_cp[i]=state[i];
      
      // Round 1
      FF (state, x[ 0], S11, 0xd76aa478); 
      FF (state, x[ 1], S12, 0xe8c7b756);
      FF (state, x[ 2], S13, 0x242070db);
      FF (state, x[ 3], S14, 0xc1bdceee);
      FF (state, x[ 4], S11, 0xf57c0faf);
      FF (state, x[ 5], S12, 0x4787c62a);
      FF (state, x[ 6], S13, 0xa8304613);
      FF (state, x[ 7], S14, 0xfd469501);
      FF (state, x[ 8], S11, 0x698098d8);
      FF (state, x[ 9], S12, 0x8b44f7af);
      FF (state, x[10], S13, 0xffff5bb1);
      FF (state, x[11], S14, 0x895cd7be);
      FF (state, x[12], S11, 0x6b901122);
      FF (state, x[13], S12, 0xfd987193);
      FF (state, x[14], S13, 0xa679438e);
      FF (state, x[15], S14, 0x49b40821);

      // Round 2
      GG (state, x[ 1], S21, 0xf61e2562);
      GG (state, x[ 6], S22, 0xc040b340);
      GG (state, x[11], S23, 0x265e5a51);
      GG (state, x[ 0], S24, 0xe9b6c7aa);
      GG (state, x[ 5], S21, 0xd62f105d);
      GG (state, x[10], S22,  0x2441453);
      GG (state, x[15], S23, 0xd8a1e681);
      GG (state, x[ 4], S24, 0xe7d3fbc8);
      GG (state, x[ 9], S21, 0x21e1cde6);
      GG (state, x[14], S22, 0xc33707d6);
      GG (state, x[ 3], S23, 0xf4d50d87);
      GG (state, x[ 8], S24, 0x455a14ed);
      GG (state, x[13], S21, 0xa9e3e905);
      GG (state, x[ 2], S22, 0xfcefa3f8);
      GG (state, x[ 7], S23, 0x676f02d9);
      GG (state, x[12], S24, 0x8d2a4c8a);

      // Round 3
      HH (state, x[ 5], S31, 0xfffa3942);
      HH (state, x[ 8], S32, 0x8771f681);
      HH (state, x[11], S33, 0x6d9d6122);
      HH (state, x[14], S34, 0xfde5380c);
      HH (state, x[ 1], S31, 0xa4beea44);
      HH (state, x[ 4], S32, 0x4bdecfa9);
      HH (state, x[ 7], S33, 0xf6bb4b60);
      HH (state, x[10], S34, 0xbebfbc70);
      HH (state, x[13], S31, 0x289b7ec6);
      HH (state, x[ 0], S32, 0xeaa127fa);
      HH (state, x[ 3], S33, 0xd4ef3085);
      HH (state, x[ 6], S34,  0x4881d05);
      HH (state, x[ 9], S31, 0xd9d4d039);
      HH (state, x[12], S32, 0xe6db99e5);
      HH (state, x[15], S33, 0x1fa27cf8);
      HH (state, x[ 2], S34, 0xc4ac5665);

      // Round 4
      II (state, x[ 0], S41, 0xf4292244);
      II (state, x[ 7], S42, 0x432aff97);
      II (state, x[14], S43, 0xab9423a7);
      II (state, x[ 5], S44, 0xfc93a039);
      II (state, x[12], S41, 0x655b59c3);
      II (state, x[ 3], S42, 0x8f0ccc92);
      II (state, x[10], S43, 0xffeff47d);
      II (state, x[ 1], S44, 0x85845dd1);
      II (state, x[ 8], S41, 0x6fa87e4f);
      II (state, x[15], S42, 0xfe2ce6e0);
      II (state, x[ 6], S43, 0xa3014314);
      II (state, x[13], S44, 0x4e0811a1);
      II (state, x[ 4], S41, 0xf7537e82);
      II (state, x[11], S42, 0xbd3af235);
      II (state, x[ 2], S43, 0x2ad7d2bb);
      II (state, x[ 9], S44, 0xeb86d391);
      
      for (int i=0; i<4; i++) state[i]+=state_cp[i];
   }*/



    /** Calculates the MD5. */
    public static byte[] digest(byte[] buffer, int offset, int len)
    {  MD5 md5=new MD5(buffer,offset,len);
        return md5.doFinal();
    }


    /** Calculates the MD5. */
    public static byte[] digest(byte[] buffer)
    {  return digest(buffer,0,buffer.length);
    }


    /** Calculates the MD5. */
    public static byte[] digest(String str)
    {  MD5 md5=new MD5(str);
        return md5.doFinal();
    }


    /** Gets the message-digest as string of hex values */
   /*public String asHex()
   {   return asHex(doFinal());
   }*/


    /** Transforms an array of bytes into a string of hex values */
   /*public static String asHex(byte[] buf)
   {  String str=new String();
      for (int i=0; i<buf.length; i++)
      {  str+=Integer.toHexString((buf[i]>>>4)&0x0F);
         str+=Integer.toHexString(buf[i]&0x0F);
      }
      return str;
   }*/

}
